In the past, there has been proposed a so-called hybrid construction machine that generates power by the drive of an engine, stores the generated power in an electrical storage device, and assists the drive of the engine using the stored power. For example, a generator, an electrical storage device, and an inverter, which controls charge and power supply between these, are closely disposed in a centralized configuration in a construction machine disclosed in the following PTL 1, so that the lengths of wires connecting electrical devices are short.